Non-neoplastic Disorders of the Gastrointestional Tract

"Gastrointestinal pathology emerged as a subspecialty in the 1980s when endoscopy and mucosal biopsy assumed increased importance in the diagnosis and management of patients with gastrointestinal disorders. Pathologists are now expected to generate comprehensive and accurate differential diagnoses for a variety of inflammatory conditions that occur throughout the gastrointestinal tract. They play a particularly important role in the care of patients with persistent gastrointestinal symptoms, especially those who are immunosuppressed, suffer from immune-mediated conditions, or undergo treatment for malignancies. Most of these individuals require medications hat can affect the gastrointestinal tract, and emerging targeted therapies seem to cause substantial mucosal injury that may necessitate cessation of the drug. Pathologists must be able to focus on key features present in biopsy material in order to narrow the differential diagnosis and facilitate patient management. This atlas is intended to address these needs in a succinct and pragmatic fashion. It describes practical approaches to the diagnosis of inflammatory gastrointestinal disorders, including sections that discuss biopsies in the bone marrow transplant setting and newly described medication-related injuries. The reader is provided with helpful criteria to facilitate distinction between newly recognized causes of esophagitis and gastritis. Various immune-mediated conditions that cause a malabsorptive pattern in biopsy samples from the proximal small bowel, as well as those that manifest with features of chronic colitis, are extensively discussed. We have also included sections describing important inflammatory conditions of the appendix and anus that may simulate neoplasia."--